Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effecti...Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effective energy storage systems.Ad-vances in materials science have led to the develop-ment of hybrid nanomaterials,such as combining fil-amentous carbon forms with inorganic nanoparticles,to create new charge and energy transfer processes.Notable materials for electrochemical energy-stor-age applications include MXenes,2D transition met-al carbides,and nitrides,carbon black,carbon aerogels,activated carbon,carbon nanotubes,conducting polymers,carbon fibers,and nanofibers,and graphene,because of their thermal,electrical,and mechanical properties.Carbon materials mixed with conducting polymers,ceramics,metal oxides,transition metal oxides,metal hydroxides,transition metal sulfides,trans-ition metal dichalcogenide,metal sulfides,carbides,nitrides,and biomass materials have received widespread attention due to their remarkable performance,eco-friendliness,cost-effectiveness,and renewability.This article explores the development of carbon-based hybrid materials for future supercapacitors,including electric double-layer capacitors,pseudocapacitors,and hy-brid supercapacitors.It investigates the difficulties that influence structural design,manufacturing(electrospinning,hydro-thermal/solvothermal,template-assisted synthesis,electrodeposition,electrospray,3D printing)techniques and the latest car-bon-based hybrid materials research offer practical solutions for producing high-performance,next-generation supercapacitors.展开更多
With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lign...With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.展开更多
The ability to control the preparation of one-dimensional(1D)porous carbon nanorods,especially during rapid polymerization,is key to their practical application.We report a method for synthesizing 1D porous carbon nan...The ability to control the preparation of one-dimensional(1D)porous carbon nanorods,especially during rapid polymerization,is key to their practical application.We report a method for synthesizing 1D porous carbon nanorods,characterized by the formation of rod-like mi-celles that are assembled from sodium palmitate and Pluronic F127,facilitated by protonated melamine,and subsequently converted into melamine-based N-doped polymer nanorods which were carbonized to produce the corres-ponding N-doped carbon nanorods.The specific capacitance of the supercapacitor used the as-pre-pared N-doped nanorods as electrode material in a three-electrode system was calculated to be 301.66 F g^(-1) at a current density of 0.2 A g^(-1),with an ultra-high specific surface area normalized capacitance of up to 67.07μF cm^(-2).The N-doping and their one-dimensionality give the nanorods a low internal resistance and good stability,making them well suited for fundamental studies and practical applications ranging from materials chemistry to electrochemical energy storage.展开更多
A low-cost 1D cobalt-based coordination polymer(CP)[Co(BGPD)(DMSO)_(2)(H_(2)O)_(2)](Co-BD;H2BGPD=N,N'-bis(glycinyl)pyromellitic diimide;DMSO=dimethyl sulfoxide)was synthesized by a simple method,and its crystal st...A low-cost 1D cobalt-based coordination polymer(CP)[Co(BGPD)(DMSO)_(2)(H_(2)O)_(2)](Co-BD;H2BGPD=N,N'-bis(glycinyl)pyromellitic diimide;DMSO=dimethyl sulfoxide)was synthesized by a simple method,and its crystal structure was characterized.In a three-electrode system,Co-BD,as the electrode material for supercapacitors,achieved a specific capacitance of 830 F·g^(-1)at 1 A·g^(-1),equivalent to a specific capacity of 116.4 mAh·g^(-1),and exhibited high-rate capability,reaching 212 F·g^(-1)at 20 A·g^(-1).Impressively,Co-BD||rGO(reduced graphene oxide),representing an asymmetrical supercapacitor,owns a higher energy density of 14.2 Wh·kg^(-1)at 0.80 kW·kg^(-1),and an excellent cycle performance(After 4000 cycles at 1 A·g^(-1),the capacitance retention was up to 94%).CCDC:2418872.展开更多
Filter capacitors play an important role in altern-ating current(AC)-line filtering for stabilizing voltage,sup-pressing harmonics,and improving power quality.However,traditional aluminum electrolytic capacitors(AECs)...Filter capacitors play an important role in altern-ating current(AC)-line filtering for stabilizing voltage,sup-pressing harmonics,and improving power quality.However,traditional aluminum electrolytic capacitors(AECs)suffer from a large size,short lifespan,low power density,and poor reliability,which limits their use.In contrast,ultrafast supercapacitors(SCs)are ideal for replacing commercial AECs because of their extremely high power densities,fast charging and discharging,and excellent high-frequency re-sponse.We review the design principles and key parameters for ultrafast supercapacitors and summarize research pro-gress in recent years from the aspects of electrode materials,electrolytes,and device configurations.The preparation,structures,and frequency response performance of electrode materials mainly consisting of carbon materials such as graphene and carbon nanotubes,conductive polymers,and transition metal compounds,are focused on.Finally,future research directions for ultrafast SCs are suggested.展开更多
Carbon materials with adjustable porosity,controllable het-eroatom doping and low-cost have been received considerable attention as supercapacitor electrodes.However,using carbon materials with abundant micropores,a h...Carbon materials with adjustable porosity,controllable het-eroatom doping and low-cost have been received considerable attention as supercapacitor electrodes.However,using carbon materials with abundant micropores,a high surface area and a high-dopant content for an aqueous su-percapacitor with a high energy output still remains a challenge.We report the easy synthesis of interconnected carbon spheres by a polymerization re-action between p-benzaldehyde and 2,6-diaminopyridine.The synthesis in-volves adjusting the mass ratio of the copolymer and KOH activator to achieve increased charge storage ability and high energy output,which are attributed to the high ion-accessible area provided by the large number of micropores,high N/O contents and rapid ion diffusion channels in the porous structure.At a PMEC∶KOH mass ratio of 1∶1,the high electrolyte ion-adsorption area(2599.76 m^(2) g^(−1))and the N/O dopant atoms of the conductive framework of a typical carbon electrode produce a superior specific capacity(303.2 F g^(−1)@0.5 A g^(−1))giving an assembled symmetric capacitor a high energy delivery of 11.3 Wh kg^(−1)@250 W kg^(−1).This study presents a simple strategy for synthesizing microporous carbon and highlights its potential use in KOH-based supercapacitors.展开更多
In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to tha...In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to that of batteries,while maintaining a high power density.We re-port a porous carbon material produced by immersing pop-lar wood(PW)sawdust in a solution of KOH and graphene oxide(GO),followed by carbonization.The resulting mater-ial has exceptional properties as an electrode for high-en-ergy supercapacitors.Compared to the material prepared by the direct carbonization of PW,its electrical conductivity was in-creased from 0.36 to 26.3 S/cm.Because of this and a high microporosity of over 80%,which provides fast electron channels and a large ion storage surface,when used as the electrodes for a symmetric supercapacitor,it gave a high energy density of 27.9 Wh/kg@0.95 kW/kg in an aqueous electrolyte of 1.0 mol/L Na_(2)SO_(4).The device also had battery-level energy storage with maximum energy densities of 73.9 Wh/kg@2.0 kW/kg and 67.6 Wh/kg@40 kW/kg,an ultrahigh power density,in an organic electrolyte of 1.0 mol/L TEABF4/AN.These values are comparable to those of 30−45 Wh/kg for Pb-acid batteries and 30−55 Wh/kg for aqueous lithium batteries.This work indicates a way to prepare carbon materials that can be used in supercapacit-ors with ultrahigh energy and power densities.展开更多
Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an excep...Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an exceptionalspecific capacitance of 190.8 mAh·g^(-1)at 1 A·g^(-1),greatly higher than the corresponding monometallic sulfides MnS(31.7 mAh·g^(-1))and Co_(3)S_(4)(86.7 mAh·g^(-1)).Impressively,the as-assembled MnCo_(2)S_(4)||porous carbon(PC)hybridsupercapacitor(HSC),showed an outstanding energy density of 76.88 Wh·kg^(-1)at a power density of 374.5 W·kg^(-1),remarkable cyclic performance with a capacity retention of 86.8% after 10000 charge-discharge cycles at 5 A·g^(-1),and excellent Coulombic efficiency of 99.7%.展开更多
This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitor...This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitors were synthesized using the extracted solution.The first phase revealed that 3 mol/L NaCl achieved the highest extraction performance,yielding 60%Cu and 23%Fe.MgCl_(2)at 1.5 mol/L extracted 52%Cu and 27%Fe,while a combination of 0.5 mol/L MgCl_(2)and 1.6 mol/L urea yielded 57%Cu and 20%Fe.Urea effectively reduced iron levels.CuFe_(2)O_(4)-based electrodes were then successfully synthesized via a hydrothermal method using a MgCl_(2)-urea solution.Characterization studies confirmed CuFe_(2)O_(4)formation with a 2D structure and 45−50 nm wall thickness on nickel foam.Electrochemical analysis showed a specific capacitance of 725 mF/cm^(2)at 2 mA/cm^(2)current density,with energy and power densities of 12.3 mW·h/cm^(2)and 175 mW/cm^(2),respectively.These findings suggest that chalcopyrite has the potential for direct use in energy storage.展开更多
Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the str...Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the structure and electrochemical properties of electrode materials were studied in detail.The results show that the controlled synthesis requires a synergy between KMnO_(4),MnCl_(2)and AlCl_(3),and that Al^(3+)plays an important role.Compared with the pure phase MnO_(2),the crystallinity of Al-doped MnO_(2)decreases and the specific surface area increases,which provides more active sites for the electrode material.When 3 mmol Al^(3+)is added,the prepared MnO_(2)-3 has the largest specific capacitance and the highest rate performance.The energy density of the asymmetric supercapacitor(ASC)with MnO_(2)-3 as the positive electrode and activated carbon(AC)as the negative electrode can reach 18.4 W·h/kg at the power density of 400 W/kg,and the capacity can maintain 90%of the initial value after 20000 cycles,indicating that Al-doped MnO_(2)has certain practical application value.This study provides favorable guidance for MnO_(2)as a high performance electrode material.展开更多
Nitrogen doping has been widely used to improve the performance of carbon electrodes in supercapacitors,particularly in terms of their high-frequency response.However,the charge storage and electrolyte ion response me...Nitrogen doping has been widely used to improve the performance of carbon electrodes in supercapacitors,particularly in terms of their high-frequency response.However,the charge storage and electrolyte ion response mechanisms of different nitrogen dopants at high frequencies are still unclear.In this study,melamine foam carbons with different configurations of surfacedoped N were formed by gradient carbonization,and the effects of the configurations on the high-frequency response behavior of the supercapacitors were analyzed.Using a combination of experiments and first-principle calculations,we found that pyrrolic N,characterized by a higher adsorption energy,increases the charge storage capacity of the electrode at high frequencies.On the other hand,graphitic N,with a lower adsorption energy,increases the speed of ion response.We propose the use of adsorption energy as a practical descriptor for electrode/electrolyte design in high-frequency applications,offering a more universal approach for improving the performance of N-doped carbon materials in supercapacitors.展开更多
The activated carbon wound supercapacitors with TEABF4/propylene carbonate （PC） and TEABF4/acetonitrile （AN） electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior w...The activated carbon wound supercapacitors with TEABF4/propylene carbonate （PC） and TEABF4/acetonitrile （AN） electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior were investigated by cyclic voltammetry （CV） and constant current charge-discharge. Compared with the PC-based supercapacitor, the AN-based supercapacitor has higher capacitance and lower equivalent serial resistance （RES） at discharge currents ranging from 5 to 1 000 mA and 25 ℃. Moreover, temperature effects are more prominent for PC-based supercapacitor than for AN-based supereapacitor. When the measurement temperature ranges from 60 ℃to -40 ℃ the capacitance changes from 5.1 to 2.5 F and RES changes from 135 to 876 mΩ for the PC-based supercapacior, while the AN-based supercapacitor shows less change in capacitance and RES. Thus AN-based supercapacitor exhibits excellent power characteristics and temperature property.展开更多
The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capaci...The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.展开更多
Polyaniline（PANI） nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors （PLi/C） based on Li-doping polyaniline and activated carbon e...Polyaniline（PANI） nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors （PLi/C） based on Li-doping polyaniline and activated carbon electrode were fabricated and compared with the redox type capacitors （PLi/PLi） based on two uniformly Li-doping polyaniline electrodes. The electrochemical performances of the two types of supercapacitors were characterized in non-aqueous electrolyte. PLi/C supercapacitors have a wider effective energy storage potential range and a higher upper potential. At the same time, the PLi/C supercapacitor exhibits a specific capacity of 120.93 F/g at initial discharge and retains 80% after 500 cycles. The ohmic internal resistance （REs） of PLi/C supercapacitor is 5.0 Ω, which is smaller than that of PLi/PLi capacitor （5.5 Ω）. Moreover, it can be seen that EtgNBF4 organic solution is more suitable for using as organic electrolyte of PLi/C capacitor compared with organic solution containing LiPFr.展开更多
Activated carbon(AC)particles sandwiched reduced graphene oxide sheets(rGO)film has been successfully fabricated via a facile self-assemble approach.The as-formed AC/rGO film is self-standing,flexible and mechanically...Activated carbon(AC)particles sandwiched reduced graphene oxide sheets(rGO)film has been successfully fabricated via a facile self-assemble approach.The as-formed AC/rGO film is self-standing,flexible and mechanically robust,allowing to be transferred to any substrate on demand without rupture.Since AC particles effectively suppressed the restacking of the rGO sheet,AC/rGO film exhibits loose layer-by-layer stacking structures with various gaps between AC particles and rGO sheets,which is different from compact structures of pure graphene films.The as-formed gaps provide fast diffusion channels for electrolyte ions and enhanced accessible surface area of rGO.Therefore,the AC/rGO electrode delivers improved electrochemical performance over the voltage range of 0.0−3.0 V.This work offers a promising strategy to design free-standing supercapacitor electrodes based on traditional nanocarbon materials.展开更多
H+ doped polyaniline nanofibre(PH) was synthesized by interfacial polymerization and polyanilines doped with Li salt(PLI and PHLI) were prepared by immersing emeraldine base(EB) and H+ doped polyaniline in 1 mol/L LiP...H+ doped polyaniline nanofibre(PH) was synthesized by interfacial polymerization and polyanilines doped with Li salt(PLI and PHLI) were prepared by immersing emeraldine base(EB) and H+ doped polyaniline in 1 mol/L LiPF6/(EC-EMC-DMC),respectively.PH,PLI and PHLI were all characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FT-IR) spectrometry.With 1 mol/L LiPF6/(EC-EMC-DMC) as electrolyte,PH,PHLI and PLI were used as the active materials of symmetric non-aqueous redox supercapacitors.PLI shows the highest initial specific capacitance of 120 F/g(47 F/g for PH and 66 F/g for PHLI) among three samples.After 500 cycles,the specific capacitance of PLI remains 75 F/g,indicating the good cycleability.展开更多
Using the mesophase pitch as precursor, KOH and CO2 as activated agents, the activated carbon electrode material was fabricated by physical-chemical combined activated technique for supercapacitor. The influence of ac...Using the mesophase pitch as precursor, KOH and CO2 as activated agents, the activated carbon electrode material was fabricated by physical-chemical combined activated technique for supercapacitor. The influence of activated process on the pore structure of activated carbon was analyzed and 14 F supercapacitor with working voltage of 2.5 V was prepared. The charge and discharge behaviors, the properties of cyclic voltammetry, specific capacitance, equivalent serials resistance （ESR）, cycle properties, and temperature properties of prepared supercapacitor were examined. The cyclic voltammetry curve results indicate that the carbon based supercapacitor using the self-made activated carbon as electrode materials shows the desired capacitance properties. In 1 mol/L Et4NBF4/AN electrolyte, the capacitance and ESR of the supercapacitor are 14.7 F and 60 mΩ respectively, The specific capacitance of activated carbon electrode materials is 99.6 F/g; its energy density can reach 2,96 W.h/kg under the large current discharge condition, There is no obvious capacitance decay that can be observed after 5000 cycles, The leakage current is below 0,2 mA after keeping the voltage at 2.5 V for l h, Meanwhile, the supercapacitor shows desired temperature property; it can be operated normally in the temperature ranging from -40 ℃to 70 ℃,展开更多
A high-performance porous carbon material for supercapacitor electrodes was prepared by using a polymer blend method. Phenol-formaldehyde resin and gelatin were used as carbon precursor polymer and pore former polymer...A high-performance porous carbon material for supercapacitor electrodes was prepared by using a polymer blend method. Phenol-formaldehyde resin and gelatin were used as carbon precursor polymer and pore former polymer, respectively. The blends were carbonized at 800℃ in nitrogen. SEM, BET measurement and BJH method reveal that the obtained carbon possesses a mesoporous characteristic, with the average pore size between 3.0 nm and 5.0 nm. The electrochemical properties of supercapacitor using these carbons as electrode material were investigated by cyclic voltammetry and constant current charge-discharge. The results indicate that the composition of blended polymers has a strong effect on the specific capacitance. When the mass ratio of PF to gelatin is kept at 1：1, the largest surface area of 222 m2/g is obtained, and the specific capacitance reaches 161 F/g.展开更多
We report an economical approach for the fabrication of laser-produced graphene(LPG)electrodes,which results in an improved electrochemical performance.Polyimide polymer was used as the starting material for LPG synth...We report an economical approach for the fabrication of laser-produced graphene(LPG)electrodes,which results in an improved electrochemical performance.Polyimide polymer was used as the starting material for LPG synthesis and was irradiated under ambient conditions with a CO_(2) laser.The prepared LPG samples were characterized by Raman spectroscopy and FTIR,which validated the formation of multilayer graphene containing sp2 hybridized C=C bonds.FE-SEM revealed three-dimensional(3D)sheet-like structures,while HR-TEM images showed lattice planes with an interplanar spacing of approximately 0.33 nm,corres-ponding to the(002)plane of graphene.Their electrochemical performance showed a remarkable areal specific capacitance(CA)of 51 mF cm^(−2)(170 F g^(-1))at 1 mA cm^(−2)(3.3 A g^(-1))in a three-electrode configuration with 1 mol L^(−1) KOH as the aqueous electrolyte.The LPG electrodes produced an energy density of~3.5μWh cm^(−2) and a power density of~350μW cm^(−2),demonstrating signific-ant energy storage ability.They also had an excellent cycling stability,retaining 87%of their specific capacitance after 3000 cycles at 1 mA/cm^(2).A symmetric supercapacitor fabricated with LPG electrodes and the 1 mol L^(−1) KOH electrolyte had a specific capacit-ance of 23 mF cm^(−2) and showed excellent retention after 10000 cycles,showing LPG’s potential for use in supercapacitors.展开更多
A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called &q...A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.展开更多
文摘Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effective energy storage systems.Ad-vances in materials science have led to the develop-ment of hybrid nanomaterials,such as combining fil-amentous carbon forms with inorganic nanoparticles,to create new charge and energy transfer processes.Notable materials for electrochemical energy-stor-age applications include MXenes,2D transition met-al carbides,and nitrides,carbon black,carbon aerogels,activated carbon,carbon nanotubes,conducting polymers,carbon fibers,and nanofibers,and graphene,because of their thermal,electrical,and mechanical properties.Carbon materials mixed with conducting polymers,ceramics,metal oxides,transition metal oxides,metal hydroxides,transition metal sulfides,trans-ition metal dichalcogenide,metal sulfides,carbides,nitrides,and biomass materials have received widespread attention due to their remarkable performance,eco-friendliness,cost-effectiveness,and renewability.This article explores the development of carbon-based hybrid materials for future supercapacitors,including electric double-layer capacitors,pseudocapacitors,and hy-brid supercapacitors.It investigates the difficulties that influence structural design,manufacturing(electrospinning,hydro-thermal/solvothermal,template-assisted synthesis,electrodeposition,electrospray,3D printing)techniques and the latest car-bon-based hybrid materials research offer practical solutions for producing high-performance,next-generation supercapacitors.
基金National Natural Science Foundation of China(22262034)。
文摘With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.
文摘The ability to control the preparation of one-dimensional(1D)porous carbon nanorods,especially during rapid polymerization,is key to their practical application.We report a method for synthesizing 1D porous carbon nanorods,characterized by the formation of rod-like mi-celles that are assembled from sodium palmitate and Pluronic F127,facilitated by protonated melamine,and subsequently converted into melamine-based N-doped polymer nanorods which were carbonized to produce the corres-ponding N-doped carbon nanorods.The specific capacitance of the supercapacitor used the as-pre-pared N-doped nanorods as electrode material in a three-electrode system was calculated to be 301.66 F g^(-1) at a current density of 0.2 A g^(-1),with an ultra-high specific surface area normalized capacitance of up to 67.07μF cm^(-2).The N-doping and their one-dimensionality give the nanorods a low internal resistance and good stability,making them well suited for fundamental studies and practical applications ranging from materials chemistry to electrochemical energy storage.
文摘A low-cost 1D cobalt-based coordination polymer(CP)[Co(BGPD)(DMSO)_(2)(H_(2)O)_(2)](Co-BD;H2BGPD=N,N'-bis(glycinyl)pyromellitic diimide;DMSO=dimethyl sulfoxide)was synthesized by a simple method,and its crystal structure was characterized.In a three-electrode system,Co-BD,as the electrode material for supercapacitors,achieved a specific capacitance of 830 F·g^(-1)at 1 A·g^(-1),equivalent to a specific capacity of 116.4 mAh·g^(-1),and exhibited high-rate capability,reaching 212 F·g^(-1)at 20 A·g^(-1).Impressively,Co-BD||rGO(reduced graphene oxide),representing an asymmetrical supercapacitor,owns a higher energy density of 14.2 Wh·kg^(-1)at 0.80 kW·kg^(-1),and an excellent cycle performance(After 4000 cycles at 1 A·g^(-1),the capacitance retention was up to 94%).CCDC:2418872.
文摘Filter capacitors play an important role in altern-ating current(AC)-line filtering for stabilizing voltage,sup-pressing harmonics,and improving power quality.However,traditional aluminum electrolytic capacitors(AECs)suffer from a large size,short lifespan,low power density,and poor reliability,which limits their use.In contrast,ultrafast supercapacitors(SCs)are ideal for replacing commercial AECs because of their extremely high power densities,fast charging and discharging,and excellent high-frequency re-sponse.We review the design principles and key parameters for ultrafast supercapacitors and summarize research pro-gress in recent years from the aspects of electrode materials,electrolytes,and device configurations.The preparation,structures,and frequency response performance of electrode materials mainly consisting of carbon materials such as graphene and carbon nanotubes,conductive polymers,and transition metal compounds,are focused on.Finally,future research directions for ultrafast SCs are suggested.
基金financially supported by University-level key projects of Anhui University of Science and Technology(QNZD2021-04,QNZD2021-07)Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(2021yjrc22,13210572)+2 种基金Huainan Science and Technology Bureau Plan Project(2023A3111)Open Research Fund Program of Engineering Technology Research Center of Coal Resources Comprehensive Utilization(MTYJZX202204)Natural Science Research Project of Anhui Educational Committee(2023AH051184,2023AH051210)。
文摘Carbon materials with adjustable porosity,controllable het-eroatom doping and low-cost have been received considerable attention as supercapacitor electrodes.However,using carbon materials with abundant micropores,a high surface area and a high-dopant content for an aqueous su-percapacitor with a high energy output still remains a challenge.We report the easy synthesis of interconnected carbon spheres by a polymerization re-action between p-benzaldehyde and 2,6-diaminopyridine.The synthesis in-volves adjusting the mass ratio of the copolymer and KOH activator to achieve increased charge storage ability and high energy output,which are attributed to the high ion-accessible area provided by the large number of micropores,high N/O contents and rapid ion diffusion channels in the porous structure.At a PMEC∶KOH mass ratio of 1∶1,the high electrolyte ion-adsorption area(2599.76 m^(2) g^(−1))and the N/O dopant atoms of the conductive framework of a typical carbon electrode produce a superior specific capacity(303.2 F g^(−1)@0.5 A g^(−1))giving an assembled symmetric capacitor a high energy delivery of 11.3 Wh kg^(−1)@250 W kg^(−1).This study presents a simple strategy for synthesizing microporous carbon and highlights its potential use in KOH-based supercapacitors.
文摘In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to that of batteries,while maintaining a high power density.We re-port a porous carbon material produced by immersing pop-lar wood(PW)sawdust in a solution of KOH and graphene oxide(GO),followed by carbonization.The resulting mater-ial has exceptional properties as an electrode for high-en-ergy supercapacitors.Compared to the material prepared by the direct carbonization of PW,its electrical conductivity was in-creased from 0.36 to 26.3 S/cm.Because of this and a high microporosity of over 80%,which provides fast electron channels and a large ion storage surface,when used as the electrodes for a symmetric supercapacitor,it gave a high energy density of 27.9 Wh/kg@0.95 kW/kg in an aqueous electrolyte of 1.0 mol/L Na_(2)SO_(4).The device also had battery-level energy storage with maximum energy densities of 73.9 Wh/kg@2.0 kW/kg and 67.6 Wh/kg@40 kW/kg,an ultrahigh power density,in an organic electrolyte of 1.0 mol/L TEABF4/AN.These values are comparable to those of 30−45 Wh/kg for Pb-acid batteries and 30−55 Wh/kg for aqueous lithium batteries.This work indicates a way to prepare carbon materials that can be used in supercapacit-ors with ultrahigh energy and power densities.
文摘Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an exceptionalspecific capacitance of 190.8 mAh·g^(-1)at 1 A·g^(-1),greatly higher than the corresponding monometallic sulfides MnS(31.7 mAh·g^(-1))and Co_(3)S_(4)(86.7 mAh·g^(-1)).Impressively,the as-assembled MnCo_(2)S_(4)||porous carbon(PC)hybridsupercapacitor(HSC),showed an outstanding energy density of 76.88 Wh·kg^(-1)at a power density of 374.5 W·kg^(-1),remarkable cyclic performance with a capacity retention of 86.8% after 10000 charge-discharge cycles at 5 A·g^(-1),and excellent Coulombic efficiency of 99.7%.
文摘This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitors were synthesized using the extracted solution.The first phase revealed that 3 mol/L NaCl achieved the highest extraction performance,yielding 60%Cu and 23%Fe.MgCl_(2)at 1.5 mol/L extracted 52%Cu and 27%Fe,while a combination of 0.5 mol/L MgCl_(2)and 1.6 mol/L urea yielded 57%Cu and 20%Fe.Urea effectively reduced iron levels.CuFe_(2)O_(4)-based electrodes were then successfully synthesized via a hydrothermal method using a MgCl_(2)-urea solution.Characterization studies confirmed CuFe_(2)O_(4)formation with a 2D structure and 45−50 nm wall thickness on nickel foam.Electrochemical analysis showed a specific capacitance of 725 mF/cm^(2)at 2 mA/cm^(2)current density,with energy and power densities of 12.3 mW·h/cm^(2)and 175 mW/cm^(2),respectively.These findings suggest that chalcopyrite has the potential for direct use in energy storage.
基金Project(202203021221138)supported by the Collaborative Innovation Center for Shanxi Advanced Permanent Materials and Technologythe 1331 Engineering of Shanxi ProvinceFundamental Research Program of Shanxi Province,China。
文摘Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the structure and electrochemical properties of electrode materials were studied in detail.The results show that the controlled synthesis requires a synergy between KMnO_(4),MnCl_(2)and AlCl_(3),and that Al^(3+)plays an important role.Compared with the pure phase MnO_(2),the crystallinity of Al-doped MnO_(2)decreases and the specific surface area increases,which provides more active sites for the electrode material.When 3 mmol Al^(3+)is added,the prepared MnO_(2)-3 has the largest specific capacitance and the highest rate performance.The energy density of the asymmetric supercapacitor(ASC)with MnO_(2)-3 as the positive electrode and activated carbon(AC)as the negative electrode can reach 18.4 W·h/kg at the power density of 400 W/kg,and the capacity can maintain 90%of the initial value after 20000 cycles,indicating that Al-doped MnO_(2)has certain practical application value.This study provides favorable guidance for MnO_(2)as a high performance electrode material.
文摘Nitrogen doping has been widely used to improve the performance of carbon electrodes in supercapacitors,particularly in terms of their high-frequency response.However,the charge storage and electrolyte ion response mechanisms of different nitrogen dopants at high frequencies are still unclear.In this study,melamine foam carbons with different configurations of surfacedoped N were formed by gradient carbonization,and the effects of the configurations on the high-frequency response behavior of the supercapacitors were analyzed.Using a combination of experiments and first-principle calculations,we found that pyrrolic N,characterized by a higher adsorption energy,increases the charge storage capacity of the electrode at high frequencies.On the other hand,graphitic N,with a lower adsorption energy,increases the speed of ion response.We propose the use of adsorption energy as a practical descriptor for electrode/electrolyte design in high-frequency applications,offering a more universal approach for improving the performance of N-doped carbon materials in supercapacitors.
基金Project(20803095)supported by the National Natural Science Foundation of ChinaProject(2008AA03Z207)supported by the National High Technology Research and Development Program of China
文摘The activated carbon wound supercapacitors with TEABF4/propylene carbonate （PC） and TEABF4/acetonitrile （AN） electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior were investigated by cyclic voltammetry （CV） and constant current charge-discharge. Compared with the PC-based supercapacitor, the AN-based supercapacitor has higher capacitance and lower equivalent serial resistance （RES） at discharge currents ranging from 5 to 1 000 mA and 25 ℃. Moreover, temperature effects are more prominent for PC-based supercapacitor than for AN-based supereapacitor. When the measurement temperature ranges from 60 ℃to -40 ℃ the capacitance changes from 5.1 to 2.5 F and RES changes from 135 to 876 mΩ for the PC-based supercapacior, while the AN-based supercapacitor shows less change in capacitance and RES. Thus AN-based supercapacitor exhibits excellent power characteristics and temperature property.
文摘The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.
基金Project(2008AA03Z207) supported by the National High-Tech Research and Development Program of China
文摘Polyaniline（PANI） nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors （PLi/C） based on Li-doping polyaniline and activated carbon electrode were fabricated and compared with the redox type capacitors （PLi/PLi） based on two uniformly Li-doping polyaniline electrodes. The electrochemical performances of the two types of supercapacitors were characterized in non-aqueous electrolyte. PLi/C supercapacitors have a wider effective energy storage potential range and a higher upper potential. At the same time, the PLi/C supercapacitor exhibits a specific capacity of 120.93 F/g at initial discharge and retains 80% after 500 cycles. The ohmic internal resistance （REs） of PLi/C supercapacitor is 5.0 Ω, which is smaller than that of PLi/PLi capacitor （5.5 Ω）. Moreover, it can be seen that EtgNBF4 organic solution is more suitable for using as organic electrolyte of PLi/C capacitor compared with organic solution containing LiPFr.
基金Project(21673102)supported by the National Natural Science Foundation of ChinaProjects(LY18B010006,LQ19B030005)supported by the Natural Science Foundation of Zhejiang Province,China。
文摘Activated carbon(AC)particles sandwiched reduced graphene oxide sheets(rGO)film has been successfully fabricated via a facile self-assemble approach.The as-formed AC/rGO film is self-standing,flexible and mechanically robust,allowing to be transferred to any substrate on demand without rupture.Since AC particles effectively suppressed the restacking of the rGO sheet,AC/rGO film exhibits loose layer-by-layer stacking structures with various gaps between AC particles and rGO sheets,which is different from compact structures of pure graphene films.The as-formed gaps provide fast diffusion channels for electrolyte ions and enhanced accessible surface area of rGO.Therefore,the AC/rGO electrode delivers improved electrochemical performance over the voltage range of 0.0−3.0 V.This work offers a promising strategy to design free-standing supercapacitor electrodes based on traditional nanocarbon materials.
基金Project(2008AA03Z207) supported by the National Hi-tech Research and Development Program of China
文摘H+ doped polyaniline nanofibre(PH) was synthesized by interfacial polymerization and polyanilines doped with Li salt(PLI and PHLI) were prepared by immersing emeraldine base(EB) and H+ doped polyaniline in 1 mol/L LiPF6/(EC-EMC-DMC),respectively.PH,PLI and PHLI were all characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FT-IR) spectrometry.With 1 mol/L LiPF6/(EC-EMC-DMC) as electrolyte,PH,PHLI and PLI were used as the active materials of symmetric non-aqueous redox supercapacitors.PLI shows the highest initial specific capacitance of 120 F/g(47 F/g for PH and 66 F/g for PHLI) among three samples.After 500 cycles,the specific capacitance of PLI remains 75 F/g,indicating the good cycleability.
基金Project(2007BAE12800) supported by the National Supported Plan for Science and TechnologyProject(06FJ4059) supported by the Hunan Provincial Academician Foundation
文摘Using the mesophase pitch as precursor, KOH and CO2 as activated agents, the activated carbon electrode material was fabricated by physical-chemical combined activated technique for supercapacitor. The influence of activated process on the pore structure of activated carbon was analyzed and 14 F supercapacitor with working voltage of 2.5 V was prepared. The charge and discharge behaviors, the properties of cyclic voltammetry, specific capacitance, equivalent serials resistance （ESR）, cycle properties, and temperature properties of prepared supercapacitor were examined. The cyclic voltammetry curve results indicate that the carbon based supercapacitor using the self-made activated carbon as electrode materials shows the desired capacitance properties. In 1 mol/L Et4NBF4/AN electrolyte, the capacitance and ESR of the supercapacitor are 14.7 F and 60 mΩ respectively, The specific capacitance of activated carbon electrode materials is 99.6 F/g; its energy density can reach 2,96 W.h/kg under the large current discharge condition, There is no obvious capacitance decay that can be observed after 5000 cycles, The leakage current is below 0,2 mA after keeping the voltage at 2.5 V for l h, Meanwhile, the supercapacitor shows desired temperature property; it can be operated normally in the temperature ranging from -40 ℃to 70 ℃,
基金Projects(50772033,50972043) supported by the National Natural Science Foundation of ChinaProject(09JJ3095) supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(09A001) supported by the Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(2010FJ3151) supported by the Science and Research Plan of Hunan Province,ChinaProject supported by the Science and Technology Innovative Research Team in Higher Education Institution of Hunan Province,China
文摘A high-performance porous carbon material for supercapacitor electrodes was prepared by using a polymer blend method. Phenol-formaldehyde resin and gelatin were used as carbon precursor polymer and pore former polymer, respectively. The blends were carbonized at 800℃ in nitrogen. SEM, BET measurement and BJH method reveal that the obtained carbon possesses a mesoporous characteristic, with the average pore size between 3.0 nm and 5.0 nm. The electrochemical properties of supercapacitor using these carbons as electrode material were investigated by cyclic voltammetry and constant current charge-discharge. The results indicate that the composition of blended polymers has a strong effect on the specific capacitance. When the mass ratio of PF to gelatin is kept at 1：1, the largest surface area of 222 m2/g is obtained, and the specific capacitance reaches 161 F/g.
文摘We report an economical approach for the fabrication of laser-produced graphene(LPG)electrodes,which results in an improved electrochemical performance.Polyimide polymer was used as the starting material for LPG synthesis and was irradiated under ambient conditions with a CO_(2) laser.The prepared LPG samples were characterized by Raman spectroscopy and FTIR,which validated the formation of multilayer graphene containing sp2 hybridized C=C bonds.FE-SEM revealed three-dimensional(3D)sheet-like structures,while HR-TEM images showed lattice planes with an interplanar spacing of approximately 0.33 nm,corres-ponding to the(002)plane of graphene.Their electrochemical performance showed a remarkable areal specific capacitance(CA)of 51 mF cm^(−2)(170 F g^(-1))at 1 mA cm^(−2)(3.3 A g^(-1))in a three-electrode configuration with 1 mol L^(−1) KOH as the aqueous electrolyte.The LPG electrodes produced an energy density of~3.5μWh cm^(−2) and a power density of~350μW cm^(−2),demonstrating signific-ant energy storage ability.They also had an excellent cycling stability,retaining 87%of their specific capacitance after 3000 cycles at 1 mA/cm^(2).A symmetric supercapacitor fabricated with LPG electrodes and the 1 mol L^(−1) KOH electrolyte had a specific capacit-ance of 23 mF cm^(−2) and showed excellent retention after 10000 cycles,showing LPG’s potential for use in supercapacitors.
文摘A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.
